Heuristic design of U-shaped die cooling channel for producing ultra-high strength steel using hot press forming

This paper proposes an optimised cooling channel design for a U-shaped die in the hot sheet metal forming process using a heuristic method. Unlike in previous works, the parameters used in this study for optimising the cooling channel design not only consider the pitch between and diameter of cooling channels but also their distance from the tool surface and wall tool. The cooling channel design is optimised by coupling the heuristic method with finite element thermal and static analyses. The main factors to be considered in the optimisation include the highest heat transfer and the lowest stress that can be achieved by the optimum cooling channel die design. The optimum design was determined by conducting a simulation and was validated by conducting an experiment. The temperature distribution of the FEA model was at most 5% different from the experimental results. The optimum cooling channel design of hot press sheet metal forming can produce ultra-high strength steels which tensile strength and hardness are 51 and 83% greater than those of original boron steels. The heuristic method can also be applied to optimise the cooling channel die design for the production of ultra-high strength steels in the automotive manufacturing industry

In vitro effects of salicylic acid, calcium and copper ions on growth and sporulation of Ganoderma boninense

The in vitro effects of single and combined application of calcium ion (Ca2+), copper ion (Cu2+) and salicylic acid (SA) were evaluated on growth and sporulation of Ganoderma boninense. In poison medium test, T7-(Ca+Cu+SA) showed effective control of G. boninense in-vitro with EC50 and EC90 values of 1500+150+150 ppm and 2000+200+200 ppm, respectively. However, in dipping test, T3-(SA) showed effective control for G. boninense in-vitro with EC50 and EC90 values of 50 ppm and 200 ppm, respectively. Interestingly, T7 (Ca+Cu+SA) indicate effective control of G. boninense at low concentration, 500+50+50 pmm as shown by EC90 analysis. Pre treatment of Ganoderma -infected rubber wood block with 500 ppm Ca + 50 ppm Cu + 50 ppm SA reduced the number (20.14%), size (1.20 cm2) and weight of basidiocarp (0.80 g) compared to the control. This was followed by a significant reduction in weight loss of the Ganoderma–infected rubber wood block (41.85%) suggesting the inhibition of the degradative enzymatic activity of the fungus. The mixture of Cu, Ca and SA had potential to suppress growth of G. boninense in vitro.Keywords: Ganoderma boninense, calcium chloride, copper- ethylenediaminetetraacetic acid (EDTA), salicylic acid, EC50 and EC9

Structure integrity analysis on nickel-diamond blade in dicing of hard-brittle ceramic die

Dicing operation in cutting hard-brittle ceramic die using nickel-diamond blade causes cracked or chipped die, accelerated tool wear and, ultimately, shortage of blade lifetime. This study aims to analyse the structural integrity of dicing blade in terms of tool wear, surface roughness, microstructure and elements during dicing. The measurements of wear blade on the blade are made by confocal microscope, whereas surface and elemental analyses are carried out with EDX SEM. Results show that the volumetric wear rate of blade is 20%, similar to roughness. The microstructure of the blade changes with occurrence of Aluminium owing to abrasive wear mechanism during cutting

Population dynamics of mantis shrimp, Harpiosquilla harpax in the coastal waters of Pantai Remis, Perak, Peninsular Malaysia

This study estimated the length-weight relationship, sex ratio and population parameters of mantis shrimp, Harpiosquilla harpax from the coastal waters of Pantai Remis, Perak, Malaysia between February 2012 and October 2012. Total length and weight of 804 specimens of H. harpax were measured and the sex ratio was 1:0.83 (M:F). Males of H. harpax were dominant over the females throughout the study period. The value of relative growth coefficient (b) for H. harpax was 2.698 for males and 2.884 for females. For the length-weight relationship, the species exhibited negative allometric growth for males, females and combined sexes. The L∞ and K of H. harpax was 18.38 cm and 1.10 yr^-1 for males and 21.53 cm and 0.75 yr^-1 for females. The growth performance index (φ') was calculated as 2.57 for males and 2.54 for females. Total mortality (Z), natural mortality and fishing mortality was found to be 4.084 yr^-1, 2.247 yr^-1 and 1.837 yr^-1 for males whereas 3.259 yr^-1, 1.674 yr^-1, 1.585 yr^-1 for females, respectively. The recruitment pattern of the species was continuous throughout the year for males and females. The exploitation level (E) of H. harpax was estimated at 0.449 for males and 0.486 for females. It is revealed that the stock of H. harpax was very close to optimum level of exploitation (E = 0.50) in the coastal waters of Pantai Remis, Perak, Malaysia

Operational decision support system for sustainable water resource management for Sungai Selangor

The Selangor River lies on the west coast of Peninsular Malaysia, 70 km north of Kuala Lumpur. The Selangor catchment area is approximately 2000 km2 and has two major dams located in the upstream part of the catchment: Sungai Selangor Dam and Sungai Tinggi Dam. Lembaga Urus Air Selangor (LUAS) is the Malaysian government agency responsible for water resources management of the Selangor catchment, their main challenge being to balance an increase in water demand, whilst trying to manage the catchment’s environmental state. Key to this is the amount of water that is being released from the two reservoirs. The current manual decision-making process (based on staff experience) does not provide LUAS with the efficiency and accuracy that is required in a catchment where sustainability is key and water resources are not always abundant. A solution was required to improve the management of the current resources, thus reducing the need for the costly and environmentally contentious development of new infrastructure. The operational Decision Support System (DSS) for sustainable water resources management of the Sungai Selangor catchment is a non-structural tool developed to support LUAS in optimising the reservoir releases and water abstractions in the catchment; it is also known as LUAS Intelligent Support System (LiSS). LiSS is a fully automated system that is driven by a combination of live, telemetered gauged data from various sources including the InfoBanjir telemetry database and Numerical Weather Prediction (NWP) rainfall forecasts from the Malaysian Meteorological Department (MMD). Simulations are carried out automatically on an hourly basis, to calculate and forecast whether flows at Bestari Jaya Barrage near the main abstraction location (SSP1) are being maintained at the required levels. If the required flows are not met, being either too high or too low, the model is re-run using an adjusted reservoir release time series. LiSS should also be able to help LUAS in future increase the sustainability of management of water resources in the Selangor catchment. This paper describes the approach developed to support LUAS meet this objective, in a manner that can be used in real-time, and which can be transferred to other catchments in future. The advantages and disadvantages of potentially expanding this system to use ensemble forecasts, data assimilation and optimisation algorithms are discussed, along with suggestions for further research

The nutrient composition and in vitro ruminal degradability of selected local plants used as goat feed in Malaysia

A comparative study of nutrient composition and in vitro ruminal degradability of selected local plants, Macaranga sp. and Mallotus sp. was carried out and Napier grass (Pennisetum purpureum) was used as control. The results obtained from proximate analysis revealed that there were significant difference (P<0.05) of all nutrient composition for each local plant species against Napier grass. Dry matter content in Macaranga sp., Mallotus sp. and Napier grass were 50.92%, 45.41% and 13.04%, respectively. The crude protein content in Macaranga sp., Mallotus sp. and Napier grass were 7.18%, 6.78% and 3.88%, respectively. Mallotus sp. has the highest crude fat content (5.22%) followed by Macaranga sp. (4.85%) and Napier grass (2.84%). Crude fibre content in Napier grass, Mallotus sp. and Macaranga sp. were 25.38%, 15.47% and 12.00%, respectively. For the in vitro ruminal degradability, total gas produced by Napier grass, Macaranga sp. and Mallotus sp. were 31.00 ml, 28.67 ml and 23.33 ml, respectively. Acetic acid production in Mallotus sp., Napier grass and Macaranga sp. were 733.49 mM/ml, 605.61 mM/ml and 599.85 mM/ml, respectively. Propionic acid production was highest in Mallotus sp. (28.61 mM/ml) followed by Napier grass (24.45 mM/ml) and Macaranga sp. (24.23 mM/ml). As for butyric acid production, Napier grass showed the highest value (11.26 mM/ml), followed by Macaranga sp. (11.19 mM/ml) and Mallotus sp. (10.36 mM/ml). However, there was no significant difference shown in acetic, propionic and butyricacids production. Thus, based on the nutrient composition and in vitro ruminal degradability results, it shows that these local plants could be used as an alternative feed source for goats

Effects of elevated temperature on high performance concrete incorporating of metakaolin and garnet

Durability has become one of the major indicators to dictate a good quality of concrete. Rapid growing in construction leads to the demand of high strength concrete which can bear high stress and high resistance towards any hazard and harsh environment thus providing a safe structure. High performance concrete (HPC) has been identified as one of the advanced types of concrete that can fulfill the criteria. Hence, in this study resistance towards elevated temperature of HPC incorporating 10% of metakaolin as part of cementitious material and 50% of garnet as part of replacement of fine aggregates were investigated. Samples of HPC with metakaolin and garnet (HPCMG) and HPC with metakaolin (HPCM) were exposed to different heating temperature of 200°C, 400°C, 600°C and 800°C for duration of one hour. The changes of physical in color and the appearances of cracks in all samples were closely observed. In addition, compressive strength tests according to BS1881-116:1983 and percentage of weight loss for all the samples were also monitored in this study. Results showed that as the temperature increased, significance losses of compressive strength were detected for both HPCMG and HPCM. At the temperature of 800°C, HPCMG degenerated 86.8% of its strength compared to 71.8% for HPCM. As temperature increased, weight loss of HPCM indicated higher reading compared to HPCMG. Major changes of the physical appearances were also detected in both HPCM and HPCGM samples such as cracks and increment in gap width on the samples. This summarized that HPCM has better fire resistance compared to HPCMG

The effect of feed-based vaccination on tilapia farm endemic for streptococcosis

A tilapia farm experiencing endemic streptococcosis was selected to study the effect of vaccination with a feed-based vaccine on naturally ocurring streptococcosis. A total of 9000 red tilapia, Oreochromis niloticus × Oreochromis mossambicus of 100 ± 20 g were divided into 9 cages. Fish of Group 1 in cages 1, 2 and 3 were not vaccinated. Group 2 in cages 4, 5 and 6 were vaccinated on days 0 and 14 (single booster) while Group 3 in cages 7, 8 and 9 were vaccinated on days 0, 14 and 42 (double booster). Vaccination was done by oral administration of the feed-based bacterin vaccine at 4% bodyweight. Samples of serum for antibody study and the brain, eyes and kidney for bacterial isolation were collected at 14-day intervals. The study was carried out during the critical months between April and June. Following vaccination and booster, there was significant (p < 0.05) increase in the antibody levels in all vaccinated groups from week 1 that reached the peak at week 3 before declining gradually until week 6. However, second booster on week 6 significantly (p < 0.05) increased the antibody level that remained high until the end of the 16-week study period (double booster). Streptococcus agalactiae was isolated at the start of the experiment (day 0) at an average of 10 ± 5.0% of the sampled fish. In week 4, the isolation rate was 13 ± 5.7% but increased to 18 ± 7.6% in week 8, to 25 ± 10.0% in week 10, to 28 ± 5.8% in week 12 and 25 ± 7.3% in week 14. The average isolation rate was 28 ± 7.2%, 18 ± 7.1% and 13 ± 8.2% of the fish sampled from unvaccinated, single booster and double booster groups, respectively. At the end of the study period, the survival rate was 45.2 ± 2.45% for unvaccinated, 65.3 ± 4.8% for single booster and 75.1 ± 2.1% for double booster groups. Vaccinating fish in endemic farm might not eliminate the disease but was able to significantly improve the survival rate